<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Gdata
 * @subpackage App
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Feed.php 16971 2009-07-22 18:05:45Z mikaelkael $
 */

/**
 * @see Zend_Gdata_App_Entry
 */
require_once 'Zend/Gdata/App/Entry.php';

/**
 * @see Zend_Gdata_App_FeedSourceParent
 */
require_once 'Zend/Gdata/App/FeedSourceParent.php';

/**
 * Atom feed class
 *
 * @category   Zend
 * @package    Zend_Gdata
 * @subpackage App
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Gdata_App_Feed extends Zend_Gdata_App_FeedSourceParent
implements Iterator, ArrayAccess
{

	/**
	 * The root xml element of this data element
	 *
	 * @var string
	 */
	protected $_rootElement = 'feed';

	/**
	 * Cache of feed entries.
	 *
	 * @var array
	 */
	protected $_entry = array();

	/**
	 * Current location in $_entry array
	 *
	 * @var int
	 */
	protected $_entryIndex = 0;

	/**
	 * Make accessing some individual elements of the feed easier.
	 *
	 * Special accessors 'entry' and 'entries' are provided so that if
	 * you wish to iterate over an Atom feed's entries, you can do so
	 * using foreach ($feed->entries as $entry) or foreach
	 * ($feed->entry as $entry).
	 *
	 * @param  string $var The property to get.
	 * @return mixed
	 */
	public function __get($var)
	{
		switch ($var) {
			case 'entries':
				return $this;
			default:
				return parent::__get($var);
		}
	}

	/**
	 * Retrieves the DOM model representing this object and all children
	 *
	 * @param DOMDocument $doc
	 * @return DOMElement
	 */
	public function getDOM($doc = null, $majorVersion = 1, $minorVersion = null)
	{
		$element = parent::getDOM($doc, $majorVersion, $minorVersion);
		foreach ($this->_entry as $entry) {
			$element->appendChild($entry->getDOM($element->ownerDocument));
		}
		return $element;
	}

	/**
	 * Creates individual Entry objects of the appropriate type and
	 * stores them in the $_entry array based upon DOM data.
	 *
	 * @param DOMNode $child The DOMNode to process
	 */
	protected function takeChildFromDOM($child)
	{
		$absoluteNodeName = $child->namespaceURI . ':' . $child->localName;
		switch ($absoluteNodeName) {
			case $this->lookupNamespace('atom') . ':' . 'entry':
				$newEntry = new $this->_entryClassName($child);
				$newEntry->setHttpClient($this->getHttpClient());
				$newEntry->setMajorProtocolVersion($this->getMajorProtocolVersion());
				$newEntry->setMinorProtocolVersion($this->getMinorProtocolVersion());
				$this->_entry[] = $newEntry;
				break;
			default:
				parent::takeChildFromDOM($child);
				break;
		}
	}

	/**
	 * Get the number of entries in this feed object.
	 *
	 * @return integer Entry count.
	 */
	public function count()
	{
		return count($this->_entry);
	}

	/**
	 * Required by the Iterator interface.
	 *
	 * @return void
	 */
	public function rewind()
	{
		$this->_entryIndex = 0;
	}

	/**
	 * Required by the Iterator interface.
	 *
	 * @return mixed The current row, or null if no rows.
	 */
	public function current()
	{
		return $this->_entry[$this->_entryIndex];
	}

	/**
	 * Required by the Iterator interface.
	 *
	 * @return mixed The current row number (starts at 0), or NULL if no rows
	 */
	public function key()
	{
		return $this->_entryIndex;
	}

	/**
	 * Required by the Iterator interface.
	 *
	 * @return mixed The next row, or null if no more rows.
	 */
	public function next()
	{
		++$this->_entryIndex;
	}

	/**
	 * Required by the Iterator interface.
	 *
	 * @return boolean Whether the iteration is valid
	 */
	public function valid()
	{
		return 0 <= $this->_entryIndex && $this->_entryIndex < $this->count();
	}

	/**
	 * Gets the array of atom:entry elements contained within this
	 * atom:feed representation
	 *
	 * @return array Zend_Gdata_App_Entry array
	 */
	public function getEntry()
	{
		return $this->_entry;
	}

	/**
	 * Sets the array of atom:entry elements contained within this
	 * atom:feed representation
	 *
	 * @param array $value The array of Zend_Gdata_App_Entry elements
	 * @return Zend_Gdata_App_Feed Provides a fluent interface
	 */
	public function setEntry($value)
	{
		$this->_entry = $value;
		return $this;
	}

	/**
	 * Adds an entry representation to the array of entries
	 * contained within this feed
	 *
	 * @param Zend_Gdata_App_Entry An individual entry to add.
	 * @return Zend_Gdata_App_Feed Provides a fluent interface
	 */
	public function addEntry($value)
	{
		$this->_entry[] = $value;
		return $this;
	}

	/**
	 * Required by the ArrayAccess interface
	 *
	 * @param int $key The index to set
	 * @param Zend_Gdata_App_Entry $value The value to set
	 * @return void
	 */
	public function offsetSet($key, $value)
	{
		$this->_entry[$key] = $value;
	}

	/**
	 * Required by the ArrayAccess interface
	 *
	 * @param int $key The index to get
	 * @param Zend_Gdata_App_Entry $value The value to set
	 */
	public function offsetGet($key)
	{
		if (array_key_exists($key, $this->_entry)) {
			return $this->_entry[$key];
		}
	}

	/**
	 * Required by the ArrayAccess interface
	 *
	 * @param int $key The index to set
	 * @param Zend_Gdata_App_Entry $value The value to set
	 */
	public function offsetUnset($key)
	{
		if (array_key_exists($key, $this->_entry)) {
			unset($this->_entry[$key]);
		}
	}

	/**
	 * Required by the ArrayAccess interface
	 *
	 * @param int $key The index to check for existence
	 * @return boolean
	 */
	public function offsetExists($key)
	{
		return (array_key_exists($key, $this->_entry));
	}

	/**
	 * Retrieve the next set of results from this feed.
	 *
	 * @throws Zend_Gdata_App_Exception
	 * @return mixed|null Returns the next set of results as a feed of the same
	 *          class as this feed, or null if no results exist.
	 */
	public function getNextFeed()
	{
		$nextLink = $this->getNextLink();
		if (!$nextLink) {
			require_once 'Zend/Gdata/App/HttpException.php';
			throw new Zend_Gdata_App_Exception('No link to next set ' .
            'of results found.');
		}
		$nextLinkHref = $nextLink->getHref();
		$service = new Zend_Gdata_App($this->getHttpClient());

		return $service->getFeed($nextLinkHref, get_class($this));
	}

	/**
	 * Retrieve the previous set of results from this feed.
	 *
	 * @throws Zend_Gdata_App_Exception
	 * @return mixed|null Returns the previous set of results as a feed of
	 *          the same class as this feed, or null if no results exist.
	 */
	public function getPreviousFeed()
	{
		$previousLink = $this->getPreviousLink();
		if (!$previousLink) {
			require_once 'Zend/Gdata/App/HttpException.php';
			throw new Zend_Gdata_App_Exception('No link to previous set ' .
            'of results found.');
		}
		$previousLinkHref = $previousLink->getHref();
		$service = new Zend_Gdata_App($this->getHttpClient());

		return $service->getFeed($previousLinkHref, get_class($this));
	}

	/**
	 * Set the major protocol version that should be used. Values < 1 will
	 * cause a Zend_Gdata_App_InvalidArgumentException to be thrown.
	 *
	 * This value will be propogated to all child entries.
	 *
	 * @see _majorProtocolVersion
	 * @param (int|NULL) $value The major protocol version to use.
	 * @throws Zend_Gdata_App_InvalidArgumentException
	 */
	public function setMajorProtocolVersion($value)
	{
		parent::setMajorProtocolVersion($value);
		foreach ($this->entries as $entry) {
			$entry->setMajorProtocolVersion($value);
		}
	}

	/**
	 * Set the minor protocol version that should be used. If set to NULL, no
	 * minor protocol version will be sent to the server. Values < 0 will
	 * cause a Zend_Gdata_App_InvalidArgumentException to be thrown.
	 *
	 * This value will be propogated to all child entries.
	 *
	 * @see _minorProtocolVersion
	 * @param (int|NULL) $value The minor protocol version to use.
	 * @throws Zend_Gdata_App_InvalidArgumentException
	 */
	public function setMinorProtocolVersion($value)
	{
		parent::setMinorProtocolVersion($value);
		foreach ($this->entries as $entry) {
			$entry->setMinorProtocolVersion($value);
		}
	}

}
